Fan



-March 19, 1929. c, HOWE 1,706,163

FAN

Filed June 15, 1927 five? (D an a UNITED STATES PATENTOFIF-I'CE.

I'm G. HOWE, OI P ASADENA, OALH'OBNIA.

IAN. i

I Application am June 1'5,

This invention relates generally to power driven rotar fans, with more articular reference to improvements in the an shown and described in my prior Patent, No. 1,247,838, of November 27, 1917.

The device of my prior atent, like the one shown and described erein, was designed to eliminate the objectionable attributes of a fan which funct oned only through its potential capacity to develop a more or less powerful .current of air in one general directwh-this direction being either constant or continuously deflected by bodily oscillation of the rotating fan blades through a predetermined arc.

This and other objections were largely overcome bythe device of my prior patent through the provision of fan blades of such configuration, disposition and movement as to radiate air currents, not only horizontally in all directions but in all directions between the horizontal and the vertical, thereby not only so modifying the velocity of the air currents as to insure the end desired, without superfluous or objectionalbly sudden, results, in their effect u on bodies against which they are directe but also generating air currents the direction of which is predetermined to. conform to the hygienic principles of ventilation and air 7 diffusion.

In practice, however, I have found that the directing of air currents of any appre-' ciable intensity above what may be termedthe horizontal plane .of the fan is not only F ,unnecessary, but curtails, to a flglreat or less degree, maximum dlfi'usive' e clency. If

currents are radiated vertically as well as horizontally, including all directions between the vertical and the horizontal, it will be apparent that current will meet ourrentto produce merel a more or less heterogeneous mullin of t e air; whereas, if the 3urrents are radiated horizontally only, when they reach the side walls of the room or chamber they will be deflected upwardly, pursuing the course of least resistance, and in the absence of counteracting currents downwardly deflected from an upwardly directing source, the driven air will be returned to and drawn into the fan for re- I distribution in the same manner-with the 1927. Serial 110. 199,015.

Therefore, jects of the nation, so far as practical and expedient, of the more pronounced upwardly directed air currents energized by the fan of my prior patent, at the same-time providin an inone of the more important job take at the top as well as the bottom of the fan, thereby not only intensifying the substantially horizontally directed currents through enhanced air supply, but creating present invention is the elimi reflex currents into the fan from above and thus establishing continuously homogeneous 'tion, in 'which- .Fig. 1 isa-side elevation of a practical and convenient embodiment of the invention;

Fig. 2 is a similar view, on an enlarged scale, of the fan by itself, without the support, driving mechanism and protecting guard or cage;

Fig. 3 is a side] view, on a still further enlarged scale of one of the fan blades;

Fig. 4 is a fragmentary edge view of the upper portion of the same, and

ig. '5 is a transverse section taken substantially on the line 55. ofFig. 4.

Referring now to the drawings in detail, numeral 7 designates the housing of an electric motor of any preferred standard make or construction and which, as it forms no part of the present invention, need not be described in detail here. This motor is designed to' be connected in any common and well-known manner with a suitable source of electric energy, and is. preferably provided with a base '8 in order that the device as a whole may be stably supported upon a .for the sheet-metal fan blades 13, 13.

The motor shaft 9 is the reversed angle of deflection at the end inwardly There may be any desired number of these fan blades. I prefer to employ four, identical in size and shape and best illustrated in Figs. 3 and 4. The major middle portion 1 1 of each'blade 13 is deflected from a radial disposition in a direction opposite that "of its normal rotary movement in order to end of the blade 13 this deflection from the radial is reversed, through symmetrical torsional curvature, in order that an adequate supply of air ma bedrawn into the space between the bla es from both above and below the fan proper. In order to insure maximum effect of rotation of the blades, a maximum area of each blade should contribute to the generation of outwardly directed currents. 'Atthe same time, this maximum efiect cannot be secured in the absence of an intake of air for distribution of corresponding capacity. Consequently, not only portions 15, 15 of the blades of importance, but also the location and abrupt-mess of the lateral or torsional curvature at 16.

Referring to Fig. 3 the inner edge of the blade is shown at 15, and the outer edge at 1 1, and, the middle portion of the blade is coming towards the observer, said blade being supposed to be arranged on a vertical axis passing through or near the upper and lower ends of the blade. The result of this is that the middle portion of the blade forces air horizontally to the ri ht as viewed in said figure, while the en portions of the blade, being reversely inclined, force the air along the axis of rotation of the blade.

Of course, as air is withdrawn-from the space between the blades for radial eject ment, a partial vacuum is created and this pressure variation in itself would naturally result in a constant flow of air into the fan from both above and below the same. However, the'withdrawal is continuous, and in the absence of some means for augmenting the natural replenishment the'flow of air into the fan would lag behind the discharge therefrom, curt-ailing the supply for distribution and obviously precluding maximum efliciency. Therefore, I laterally deflect the blade-endsin a direction opposite to that of the middle portion of the blade in order to, g-ugment the volume of flow of air into the However, in view of the assistance ren dered by the partial vacuum between the rotating blades, the surface area of the blade area as to permit of symmetrical torsional curvature of the blade throu h a maximum are of 90-for I have also found that if I 'make this angle of reverse deflection 45 from the radial, as best shown in Figs. 4 and 5, I can give maximum area to the effective portions of the blades, with adequate air supply, and thus secure the most effective functloning of the fan without employing blades of undue or inconvenient size.

The extreme ends 17, 17 of each blade are bent and curved to fit the tapering faces 18 and 19 of the blocks '10 and 12, respectively, where they are firmly secured by screws or rivets 20 or in any other suitable manner. It will be noted that in reversely deflecting the blade-ends from the radial to augment the air supply, I also so dispose these ends as to avoid excessive curvature or bending in providing a configuration which insures snug,

firm and dependable attachment to tl1e\ ta-' pering faces of the blocks 10 and 12.

In Fig. 1 I have shown; partly broken away, a wire guard or cage 21, of substantially spherical form, serving the usual prctective purposes without detracting from the generally pleasing appearance of the fan when in or out of use.

The device of my present invention has all of the advantages enumerated with respect to the fan of my prior patent, afore-- said, with the added advantages of greater .economy of manufacture and ease of operation, together with enhanced effectiveness size for size.

I claim as my invention:

1. A fan comprising a rotatable element and a plurality of blades mounted thereon to revolve therewith, said blades being disposed longitudinally and substantially edgewise with respect to the axis of revolution,

the middle portion of each blade being "1aterally inclined from the radial in a direction opposite toy that of its normal movement, and the end portions of said blade inclined .in the reverse -direction.

2. In a fan, the combination'of a motor having a substantially vertically disposed armature. shaft, blades mounted on 'said shaft torevolve therewith, said blades being disposed longitudinally and substantially edgewise with respect to the axis of revolution and both ends of each thereof being secured to said shaft, the middle portion of each blade. being laterally inclined from the radial ina direction opposite to that of its normal movement, and the end ortions of each blade being inclined in t e reverse direction.

3. A fan comprising a rotatable element and a plurality of blades mounted thereon to revolve therewith, said blades being dis posed longitudinally and substantially edgewise with respect to the axis of revolution, the middle portion of each blade being laterally inclined from the radial at an angle of approximately 45 in a direction opposite to that of its normal movement, and the end portions of each blade being inclined in the reverse direction.-

4. A fan comprising a rotatable element and blades mounted thereon to revolve therewith, said blades being disposed longitudinally and substantially edgewise with respect to the axis of revolution, the middle portion of each blade being laterally inclined from the radial at an angle of approximately 45 in a direction opposite to that of its normal movement, and the end portions of each blade being inclined in the reverse direction at a substantially equivalent angle.

- 5. A fan comprising a rotatable element and a plurality of blades mounted thereon to revolve therewith, said blades being disposed longitudinally and substantially edgewise with respect to the axis of revolution and both ends of each blade being secured to said rotatable element, the middle portion of each blade being laterally inclined from the radial at an angle of approximately 45 in a direction opposite to that of its normal away movement, and the end portions of each blade being inclined in the reverse direction at a substantially equivalent an le.

6. A semi-circular fan blade aving its middle portion inclined so that its inner edge is in advance of its outer edge relative to its direction of movement about an axis, and having its end portions inclined so that the outer edge of the blade is in advance of the inner edge of the blade, when the blade is moved about an axis which is located at the two ends of the blade, whereby the middle portion of said blade propels air away from said axis and both ends of said blade draw the air inward along such axis.

7. A fan comprising a rotatable element and a plurality of semi-circular blades mounted thereon to revolve therewith, each of said blades having its middle portion inclined so that its inner edge is in advance of its outer edge relative to its direction of movement, about the axis of said rotatable element, and havin its end portions inclined so that the outer e ge of the blade is in advance of the inner edge of the blade, when the blade is moved about said axis, whereby the middle portion of said blade propels air from said axis and both ends of said blade draw the air inward along such axis.

In testimony whereof I aflix my signature.

FRED G. HOWE. 

